Transanal irrigation is effective for low anterior resection syndrome: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND

The therapeutic value of transanal irrigation (TAI) for low anterior resection syndrome (LARS) has not been fully confirmed. This study aims to evaluate the efficiency of TAI in improving bowel function and quality of life (QoL) following sphincter-preserving resections (SPRs) for rectal cancer through a systematic review and meta-analysis of randomized controlled trials (RCTs).

METHODS

The protocol was registered in PROSPERO (CRD42024598219). PubMed, Embase, Web of Science, Cochrane Library, CNKI, and WanFang databases were systematically searched for RCTs comparing TAI with conservative treatments for LARS published before December 2024. Outcomes included pooled risk ratios (RRs) for dichotomous variables and weighted mean differences (WMDs) for continuous variables, calculated using Review Manager 5.4.1 with 95% confidence intervals (CIs). P < 0.05 was considered statistically significant. The I test was used to assess heterogeneity.

RESULTS

Among 123 initially identified studies, six RCTs involving 317 patients were included. Meta-analysis demonstrated that the TAI group exhibited significantly lower LARS scores (WMD = -10.35, 95% CI [-15.92, -4.78], P < 0.01). The TAI group demonstrated significantly better outcomes across all five LARS subscales compared to controls, including flatus incontinence (WMD = -0.92; 95% CI [-1.30, -0.54]; P < 0.01), liquid stool incontinence (WMD = -0.83; 95% CI [-1.07, -0.59]), frequency (WMD = -1.33; 95% CI [-1.95, -0.72]; P < 0.01), stool clustering (WMD = -4.89; 95% CI [-5.90, -3.88]), and urgency (WMD = -5.35; 95% CI [-7.12, -3.58]). There was also a significant difference in Wexner score (WMD = -2.78, 95% CI [-4.13, -1.42], P < 0.01). However, no significant differences were observed in SF-36 mental (WMD = 7.27, 95% CI [-1.61,16.15], P = 0.11) or physical component scores (WMD = 6.97, 95% CI [-1.26,15.19], P = 0.10). Heterogeneity was substantial for LARS score analysis (I = 86%) but resolved in subgroup analyses.

CONCLUSION

TAI significantly improves bowel function in patients with LARS, as evidenced by reduced LARS and Wexner scores. However, its impact on QoL remains inconclusive. Large-scale RCTs with extended follow-up periods are warranted to validate long-term clinical benefits.